Simulation and experimental investigation of dust-collecting performances of different dust exhaust hoods

High-efficiency dust collection for open dust source has always been an important and difficult issue for air quality control at the workplace. This study performed simulations and experiments on three kinds of dust exhaust hoods, namely, updraft, side-draft and air-curtain exhaust hoods. Results show these three kinds of exhaust hoods varied significantly in dust-capturing efficiency. The dust-capturing efficiency of the updraft exhaust hood was the lowest (56.8%) while the air-curtain exhaust hood performed best in dust collection, with a dust-capturing efficiency of 93.8%. For a rectangular air-curtain exhaust hood with a size of 900 mm x 1200 mm, the dust-capturing efficiency first increased and gradually tended to stabilize with increasing air-curtain velocity and suction airflow rate. According to the present research results, the reasonable long-side air-curtain velocity and suction airflow rate were in the range 4 ~ 6.27 m/s and 5.4 ~ 9 m³/min, respectively. Under these conditions, dust-capturing efficiency can be as high as 79.6-86.5%. Implications: This study performed simulations and experiments on three kinds of dust exhaust hoods: updraft, side-draft and air-curtain. Simulation results show the dust-capturing efficiency of the air-curtain exhaust hood is best of 93.8%. Experimental results show under reasonable conditions, the dust-capturing efficiency of a rectangular air-curtain exhaust hood is 79.6-86.5%. This research is very meaningful, which not only has important innovation in the study of micro mechanism of dust collectors but provides powerful theoretical and experimental support for technological innovation.